Rattle from engine but only at idle

[adam03031980]

Hi All at idle there is like a rattle or chatter that disappears when revs and creates a sort of whine it doesn’t seem to be gear or clutch related as happens whether driving or stationary and even with clutch pedal down I have an old invoice from the previous owner being quoted for a new alternator but the work was never done could it be a bearing or pulley on it. Just to reiterate this rattle or chatter disappears complete when revved or throttle blipped. One thing i have noticed is that the tensioner jumps about but it seems off the rattle goes after the throttle is blipped, i had a crabkshaft pulley changed on my other 406 but that rattle was only noticeable at high revs whereas this isnt

[adam03031980]

I forgot to say sometimes theres a slight squeak but thats not a DMF as this is a 90bhp

[Captain Jack]

Check my ongoing saga here. We seem to have the same issue.

[adam03031980]

Ive decided sod it and ordered a new tensioner, belt and crankshaft pulley for £60 and seeing as im a lazy sod my brothers a mechanic and said he'll change it for £20

[adam03031980]

The only thing thats baffling me is the whirring/whine noise that happens when revving or acceleratin could this be a pulley i have not heard this on a car before, i see from a previous owner they wer advised to get a new alternator but no reason why and no note if work was done

[Captain Jack]

See my other thread. It has been suggested that the alternator clutch pulley can seize leaving no damping for the belt. I didn't even know these pulleys were damped...

[adam03031980]

Well decided to buy a 2nd hand alternator for £20 but still have a wine though i did take of the pulley beneath the alternator and that seemed a bit rough so am thinking it may now be that but cannot believe how expensive they are, at least thats pretty easy to change